Apparatus for producing combustible gaseous mixtures at substantially constant pressures



Feb. 22, 1944. 'r. H. RANSOME 2,342,426

APPARATUS FOR PRODUCING COMBUSTIBLE GASEOUS MIXTURES AT SUBSTANTIALLYCONSTANT PRESSURES Filed Oct. 1, 1941 3 Sheets-Sheet 1 1'NVENT0R.ZhLLENT 15f fimwso/w A rroe/wr Y5,

Feb. 22, 1944. T. H. RANSOME 2,342,425

APPARATUS FOR PRODUCING COMBUSTIBLE GASEOUS MIXTURES AT SUBSTANTIALLYCONSTANT PRESSURES Filed Oct. 1, 1941 3 Sheets-Sheet 2 N m I Q l l i I aQ I .m l

i I N I II 3 l I r? I if T I i I I I 5 1 Q I WQ v I N T I m INVENTOR.ZZumwrflfiANso/wa ATTORNEYS Feb. 22, 1944. 'r. H. RANSOME APPARATUS FORPRODUCING COMBUSTIBLE GASEOUS MIXTURES AT SUBSTANTIALLY CONSTANTPRESSURES Filed Oct. 1, 1941 3 Sheets-Sheet I5 U INVENTOR. ZZLL ENT HBan/soma- BY A T'TORNEY-s v proper combustion.

Patented Feb. 22, 1944 UNITED STATES PATENT OFFICE APPARATUS FORPRODUCING COMBUSTI- BLE GASEOUS MIXTURES AT SUBSTAN- TIALLY CONSTANTPRESSURES 10 Claims.

This invention relates to apparatus for the manufacture oi a combustiblegaseous mixture.

Where hydrocarbons of the methane series, such as butane, propane, etc.,or a mixture of such gases are employed, the B. t. u. or calorific valueis ordinarily too high for most uses and a dilutent, in the form of airor other gases, must accordingly be mixed with the gas to insureApparatus for manufacturing such a dilute mixture of gases, forcontrolling the B. t. u. content and the pressure of said gases, formsthe subject matter of the present invention.

The object of the invention is generally to improve and simplify theconstruction and operation of apparatus of the character described: toprovide an apparatus which will control and maintain a substantially.constant predetermined calorific value of a gaseous mixture; to providean apparatus which will maintain a gaseous mix ture at a substantiallyconstant B. t. u. or predetermined calorific value and at asubstantially constant pressure; and further, to provide an apparatuswhich is automatic in operation throughout and capable of large capacityproduction of diluted gases.

The apparatus is shown by way of illustration in the accompanyingdrawings, in which Fig. 1 is a diagrammatic view of the apparatus; I

Fig. 2 is an enlarged end view of the apparatus, showing parts insection;

Fig. 3 is a plan view of the apparatus, showing the aspirators arrangedand controlled in pairs;

Fig. 4 shows a side elevation of Fig. 3; and

Fig. 5 shows an end view of Fig. 3.

Referring to the drawings in detail, and particularly the diagrammaticview shown in Fig. 1, A indicates a pipe line connected with a source.of gaseous fuel supply under pressure and B a service main into which adilute mixture of the gaseous fuel is to be introduced. Connected withthe service main is the discharge end of a Venturi tube 2 and mounted insaid discharge end is a shut-oil. valve 3, which is normally open, and acheck valve 4. Connected with the throat end 5 of th Venturi tube is ahousing Ii and extending through the housing and aligning with thethroat is a nozzle 1. The housing is provided with an air inlet 8 and asuitable form of air cleaner 9 may be applied to said inlet wheneverrequired.

Fbrmed between the air inlet 8 and the nozzle 1 is a valve seat II andengaging said seat i a valve II which is provided with a downwardlyextending stem II. This stem extends into a cylinder H and it isprovided with a piston l5 which has a sliding fit in the cylinder.

Connecting with the lower end of the cylinder.

or at a point below the piston I5, is a pipe I6. This pipe is alsoconnected with the nozzle 1 and is furthermore connected with the supplypipe A, as will hereinafter be described.

The gas under pressureis delivered tothe pipe l6 and the nozzle I whenthe apparatus is in operation. This pressure may be in the neighborhoodof forty, fifty or more pounds and it is utilized not only to supply thenozzle 1. but also to lift or open the valve IL, To accomplish this, theend of the pipe 18 connecting with the cylinder H is U-shaped as shownand it is filled with oil or a similar liquid medium. Thus, when gasunder pressure is supplied to the pipe l8, it will exert pressure on theoil and the oil will in turn exert pressure on the piston l5, therebylifting the valve to an open position, opening movement of the valvebeing limited by the stop or pin l I. Gas, at the same time, willdischarge through the nozzle 7 and as it enters the throat end of theventuri a suction action is produced which causes air to enter throughthe filter, the

air inlet 8, and to pass by the valve into the throat where a-mixture ofthe air and gas takes place. This mixture discharg s through the Venturitube past the check valv 4 and the normally open valve 3 and. hence,into the service main D. No leakage of gas will take place around thepiston II, as the pressure is not exerted directly on said piston but onthe oil disposed between the gas and the piston. Any small amount of oilthat'might leak by the piston will return by leakage when the apparatusis not functioning and as the oil is preferably of a viscous nature,chance, even of oil leakage, is very small.

An important feature of the present invention is the simultaneousoperation of the nozzle 1 and the valve I l For instance, if thereshould be any material lag in the opening of the valve II when gasstarts to discharge through the nozzle 1, a rich gaseous mixture wouldpass through the Venturi into the service main B and the B. t. u.content of the service main would, accordingly, increase, but by openingthe valve simultaneously with the delivery of gas to the nozzle, amixture of air and gas will instantly take plac and the B. t. u. contentin the service main will be substantially constant.

A pull spring II is connected with the valve and this automaticallycloses the valve the moment the gas supply to the pipe I! is shut oif.Hence, the'valve automatically opens with introduction of gas to thenozzle and automatically and simultaneously closes when said gas supplyis shut off.

Another feature of the present invention is to maintain a substantiallyconstant pressure in the service main. To accomplish this, a take-offpipe is provided as indicated at 20. This pipe is connected at one endwith the service main and at the opposite end with a bellows type oftube or diaphragm such as indicated at 2|. This, through a pin 22actuates a lever 23 pivoted at 24 within a housing 25. An adjustablecompression spring 26 is disposed above said lever and may be adjustedto permit the diaphragm 2| to expand and raisewith any predeterminedpressure within the service main. For instance, if it is desired tomaintain a pressure of 4 lbs. gauge in the service main, the spring 26will be adjusted to permit the diaphragm to expand and maintain thelever 23 in a raised position when a 4 lb. pressure is reached. On theother hand, if the pressure drops below 4 lbs. the diaphragm willcontract and the lever 23 will move downwardly. In so doing, it impartsa rocking movement to a mercoid tube such as indicated at 21. This is astandard type of tube containing a small quantity of mercury. When thetube assumes one tilted position, a circuit through a pair of contacts28 carried by the tube is broken and when it assumes an opposite tiltedposition, the mercury runs to the other end of the tube and closes saidcircuit through the contacts. In this particular instance, the tube ismoved by the lever 23 through means of a link 29 and when the pressurein the service main is below 4 lbs. the tube will assume a tiltedposition where the circuit through the contacts 28 is closed.Conversely, when the pressure reaches 4 lbs. the tube will be tilted inthe opposite direction and the circuit will be broken.

The circuit referred to is utilized to open and close a valve 30 whichshuts oil or supplies gas to the pipe'lG. This valve is actuated by alever 3| connected through a link 32 to the movable core 33 of asolenoid magnet 34. This magnet is actuated by the circuit establishedthrough the contacts 28 of the mercoid tube. Hence, when said circuit ismade, the solenoid will be energized and the valve 30 opened. 'Thistakes place when the pressure in the service main is below apredetermined pressure, for instance, 4 lbs. When the pressure isrestored by operation of the Venturi tube and the cooperating nozzle 1,the flexible diaphragm 2| will move to tilt the mercoid tube and breakthe circuit and when the circuit is broken, the solenoid magnet willbecome de-energized and valve 30 will close. Hence, a substantiallyuniform measure is automatically maintained in the service main and byregulating the flow of gas through the nozzle 1, for instance, by meansof valve 1', a mixture of a suitable B. t. u. content will bemaintained. This mixture may be increased or decreased in B. t. u.content byregulation of the valve 1. Hence, the B. t. u. content of thefinal mixture is also under control.

In actual practice, the pressure on the main fuel supply pipe A may be90 lbs. or more. This is usually steppeddown to a pressure of 40 or 50lbs. before it reaches the valve 30 and this is accomplished by the useof a diaphragm actuated pressure regulator of standard form such asshown at 40.

In the diagrammatic view shown in Fig. 11 only nil one Venturi tube withcooperating nozzle and air inlet valve is shown. These cooperating members form a unit commonly known as an aspirating unit. In actualpractice, particularly where the load or demand on the service main isfairly high, there will be a considerable number of aspirating unitsconnected with the service main as shown in Fig. 2 of the drawings.These units may be arranged in pairs, or larger groups, and each pairwill in that instance be controlled by a single pressure actuateddiaphragm such as shown in 2| and associated solenoid operated valves30, that is--the diaphragm 2| will in that instance control two or moreaspirating units simultaneously. On the other hand, each aspirating unitmay have an individual control, but whether the aspirators are arrangedin groups of two or more, or individually, each pair or individual unitwill be regulated by a spring 26 to open or close one or more valves 30at different pressures. For instance, the first pair indicated at C willgo on the moment the pressure in the service main drops slightly below 4lbs. gauge; if there is a further slight drop, the next pair indicatedat D will go on, etc., until practically all units are in operation aswould be the case when the demand or load on the service main hasreached full capacity.

The drop in pressure in the service main between no load and full loadmay be as small as desired. For instance, it may be as little asoneeighth lb. gauge or less, as the diaphragms 2| many be adjusted bymeans of the springs 26 to function at exceedingly slight pressurevariations: for instance, such pressure variations as are measured byinches of water. Thus, regardless of what the demand on the service maybe, the aspirating units will automatically cut in and out as the demandincreases or decreases and a substantially constant pressure will thusbe constantly maintained.

Where butane or a like gas is employed as the source of fuel, it willusually be stored in a tank under a pressure of lbs. or so, saidpressure being maintained either by heat or the application ofcompressed air. Under such a pressure the butane will be in liquid form.When drawn from the tank it will pass through heat exchangers, not hereshown, and will thus be delivered to the pipe A at a sufliciently hightemperature to maintain it in a gaseous form when entering the pressurereducing valve indicated at 40. At this point the pressure drop isconsiderable and as the gas is used valmost immediately thereafter,further heat application is usually unnecessary, but

if it should be necessary it could obviously be employed. The tank orsource of fuel supply, heat exchangers, etc., are not shown, as standardequipment of this character may be employed.

While this and other features of my invention have been more or lessspecifically described and illustrated, I nevertheless wish itunderstood that changes may be resorted to within the scope of theappended claims, and that the materials and finish of the various partsemployed may be varied according to what the experience of themanufacturer and varying conditions of use may demand.

Having thus described and illustrated my invention, what I claim andwish to secure by Letters Patent is:

1. In a gas mixing apparatus of the character described, an aspiratorhaving an air inlet valve, means for shutting off or delivering gasabove atmospheric pressure to the aspirator, a main' into which theaspirator discharges and means actuated by the withdrawal of apredetermined quantity of gas from the main for delivering gas underpressure to the aspirator and for simultaneously opening the air inletvalve.

2. In a gas mixing apparatus of the character described an aspiratorhousing having a suction producing nozzle, an air inlet valve on thehousing, said valve being normally closed, a source of gas supply aboveatmospheric pressure connected with the nozzle a normally closed valvebetween the gas source and the nozzle, 8. gas service main into whichthe aspirator discharges and means controlled by a predeterminedpressure drop in the service main for opening the valve supplying gasunder pressure to the nozzle and for simultaneously opening the airinlet valve.

3. In a gas mixing apparatus of the character described an aspiratorhousing having a suction producing nozzle, an air inlet valve on thehousing, said valve being normally closed, a source of gas supply a'boveatmospheric pressure connected with the nozzle a normally closed valvebetween the gas source and the nozzle, a gas service main into which theaspirator discharges. means controlled by pressure variations in theservice main to shut oil or open the valve supplying gas to the nozzleand means actuated by gas under pressure supplied to the nozzle forcausing simultaneous closing or opening the air inlet valve.

4. In a gas mixing apparatus of the character described an aspiratorhousing having a suction producing nozzle, an air inlet valve in thehousing, said valve being normally closed, a source of gas supply aboveatmospheric pressure connected with the nozzle, a gas service main intowhich the aspirator discharges, means actuated by pressure changes inthe service main for opening or closing an electric switch, and meansactuated by the breaking or making of an electric circuit controlled bysaid switch for shutting off or supplying gas under pressure to thenozzle and for simultaneously shutting oil or opening the air inletvalve.

5. In a gas mixing apparatus of the character described a plurality ofaspirator housings each having a suction producing nozzle, an air inletvalve on each housing, said valves being normally closed, a source ofgas supply above atmospheric pressure connected with each nozzle, a gasservice main into which the several aspirators discharge meanscontrolled by a pressure drop below a predetermined pressure in theservice main for supplying gas under pressure successively to theseveral nozzles and for simultaneously opening the air inlet valveassociated with each nozzle said means shutting off the gas supply tothe several nozzles in succession when the pressure increases in theservice main, and simultaneously shutting off each air inlet valve whenthe gas supply to the associated nozzle is shut oil.

6. In a gas mixing apparatus of the character described, a Venturi tube,a housing connected with the throat end of the tube, a gas service mainconnected with the opposite end of the tube, a suction producing nozzleextending into the housing and aligning with the throat of the tube, asource of gas supply under pressure connected with the nozzle, anormally closed valve between the gas source and the nozzle, an airinlet valve for the housing, a piston connected with the valve, acylinder for the piston, a liquid in the cylinder on one side of thepiston, a spring normally maintaining the valve closed, and

means controlled by a pressure drop in the service main to openthe valvesupplying gas to the nozzle, and for simultaneously applying gaspressure on the liquid in the cylinder to open the air inletvalve, saidmeans automatically causing shutting off of both valves when apredetermined high pressure is developed in the service main.

7. In a gas mixing apparatus of the character described, a. plurality ofaspirator housings each having a suction producing nozzle, an air inletvalve on each housing, said valves being normally closed, a source ofgas supply under pressure connected with each nozzle, a normally closedgas supplying valve between each nozzle and the source of gas supply, agas service main into which the several aspirators discharge, a pressureactuated device for each aspirator, said pressure actuating devicesbeing connected with the gas service main, an electric switchcooperating with each pressure actuating device and adapted to be openedor closed thereby, means for adjusting the individual pressure actuateddevices to operate in succession at difierent pressures in the gasservice main, said pressure actuating devices when actuated closing anelectric circuit through an associated electric switch,

means actuated by the closing of a circuit for opening an associated gassupplying valve to deliver gas under pressure to an associated nozzle,and means actuated by gas under pressure supplied to a nozzle forsimultaneously opening an associated air inlet valve.

8. In a gas mixing apparatus of the character described an aspiratorhousing having a suction producing nozzle, a normally closed air inletvalve for the aspirator, a source of gas supply under pressure connectedwith the nozzle, a normally closed valve in said connection, a gasservice main into which the aspirator discharges, electrically actuatedmeans for opening the valve controlling the flow of gas to the nozzle, apressure actuated device connected with the gas service main, means foradjusting the pressure actuated device to operate at a predeterminedpressure in the gas service main, an electric switch opened or closed bythe pressure actuated device, said switch making or breaking an electriccurrent to operate the electrically actuated means for opening orclosing of the valve controlling the flow of gas to the aspiratornozzle, and means actuated by the gas under pressure when admitted tothe nozzle for simultaneously opening the air inlet valve.

9. In a gas mixing apparatus of the character described an aspiratorhousing having a suction producing nozzle, means connecting said nozzlewith a source of gas supply under pressure, a normally closed air inletvalve for the aspirator housing, gas pressure actuated means connectedwith the source of supply for opening said air inlet valve, a gasservice main into which the aspirator discharges, avalve normallyclosing the flow of gas from the source of supply to the aspiratornozzle and to the gas pressure actuating means for opening the air inletvalve, and means controlled by a predetermined pressure drop in theservice main for opening said last named valve so as to simultaneouslydeliver gas under pressure to the nozzle and to open the air inletvalve.

10; In a gas mixing apparatus of the character described an aspiratorhousing having a suction producing nozzle, an air inlet valve for saidhousing said valve being normally closed, a source of gas supply underpressure connected with'the nozzle, a normally closed valve between thenozzle and the source of gas supply, a gas service main into which theaspirator discharges, a pressure actuated device for the aspirator.saidpressure actuated device being connected with the gas service main,an electric switch cooperating with said pressure actuated device andadapted to be opened or closed thereby, means for adjusting the pressureactuating device to operate 10 at a predetermined drop of pressure inthe gas service main, said pressure actuated device when actuatedclosing an electric circuit through an associated electric switch, meansactuated by the closing of the circuit for opening the gas supplyingvalve to deliver gas under pressure to the nozzle, and means actuated bythe gas under pressure supplied to the nozzle for simultaneously openingthe air inlet valve.

TALLENT H. RANSOME.

